Upon doing some deconstruction on a previous built rod I’m assuming you would classify these guide tunnels as not being filled with epoxy correct? I always do saturating coats before removing excess epoxy for my first coat.

It's hard to say, really. I will just say that any time I have stripped guides off of one of my builds, either to change the type of guide being used, or to change thread color, the foot of the guide looks like it was placed in a bed of finish. It's not completely under the foot of the guide itself, but it comes up the sides of the foot.

Can I ask if you had applied CP on the thread before applying the finish? The reason I ask is, and it's hard to tell, but the blank looks very clean on the area of the blank away from where the guide tunnel would be. The only time I've had the blank that clean on a wrap I have stripped, is when I have stripped a test wrap that I had applied CP to it, before applying finish.

I used to have trouble with bubbles in the finish that formed along the sides of the guide feet. At that time I had never paid attention to filling the guide tunnels. I just applied the finish, thinking that's all I needed to do. After dealing with that for my first three builds I started reading threads dealing with builders having trouble with bubbles forming on their wraps. The remedy that fixed it for me, was to apply finish to just the area of the guide tunnels first, and to give it time to soak in before continuing to apply finish. Once I started doing that, my problems with bubbles in that area went completely away.

I never had problems with bubbles in the guide tunnel area on my running guides, because the guide foot is so much thinner in height on running guides. It was only on the guides that had thicker feet. Like the one in your picture.

I'm a fly rod guy so I usually don't deal with feet quite that long.

That said, for stripping guides that have the longest feet on my builds, I (1) make sure the first coat of whatever (epoxy or spar) is sufficiently thin and (2) before starting the initial coat I snake a piece of mono into the tunnel from the open side of the wrap. The is udually a piece of 1X-ish mono bent like a "U" running down either side of the guide foot.

After I put on my initial coat, I use the mono almost like a flexible bobbin so-to-speak to push the coating all the way into the tunnel. You can usually see the saturation occurring on the top of the wrap. I discard the mono, finish the coat, and do every follow coat normally without any need for the mono trick. I'm sure others do something similar using a potentially better approach but this works for me.

IMO - guide tunnels MUST be completely filled to better support and immobilize the guide.
I do that by filling the tunnels BEFORE I apply finish on any other part of the wrap.
I put generous drops of finish at all four openings of my stripper and all other 2 footed ceramic guides.
DO NOT let the finish get fully wicked into the tunnels because you will pull in bubbles.
Keep refreshing the pool of finish until it is wicked all the way to the tip of the guide foot.
Only then do I apply Finnish to the rest of the wrap.
Herb
CTS Rep.